This invention relates to an automatic mounting and dismounting apparatus of an attachment onto and from a spindle head or a ram of a machine tool.
Among prior art apparatus for automatic mounting and dismounting apparatus of an attachment such as an angle head onto and from a spindle head or a ram of a machine tool having a rotatable spindle are included:
A. Apparatus for clamping a plurality of pull studs provided for the attachment with a collet provided for the spindle head,
B. Apparatus wherein the flange of the attachment to the end surface of the spindle head with a nut runner is bolted, and
C. Apparatus wherein T shaped bolts provided for the spindle head are inserted and withdrawn into and out of T shaped grooves provided for the attachment and rotated in the T shaped grooves for securing the attachment to the spindle head.
However, with apparatus A, the clamping strength is not sufficient at the time of heavy cutting performed by a large machine tool, and moreover at the time of turning the attachment while indexing the same before completely removing the attachment from the spindle head it is necessary to move the attachment relative to the collet over a relatively large distance. Apparatus B not only requires a special nut runner, but also at the time of indexing the attachment, it is necessary to dismount the attachment from the spindle head and then to swing the attachment by using an external mechanism which increases the size of the apparatus and requires a long time for mounting and dismounting the attachment. In apparatus C, a complicated drive mechanism is necessary for synchronously swinging the T shaped bolts in synchronism with the T shaped grooves.